Respiration assembly and methods

ABSTRACT

A respiration assembly and methods, the assembly comprising only a few nebulizing and exhalation valve components, force-fit together and disposable after short usage. Air is delivered during the inspiration phase of the respiration cycle from a conventional respirator to the assembly in the form of a low pressure main stream flow and a high pressure nebulizing flow, the exhalation valve being closed by distending an expandable bladder under pressure. Nebulization occurs by discharging the high pressure flow through a constriction causing fluid from a cup reservoir to be siphoned to the site of discharge where shearing action of the effluent air against the liquid results in an aerosol of small liquid particles. The aerosol is further broken up by a baffle, disposed immediately downstream of the orifice within the cup reservoir. The aerosol is purged from the cup reservoir and carried to and mixed with the main stream air flow by diverting a portion of the main stream flow through the cup. During the expiration phase of the respiration cycle, no air flow occurs, the exhalation valve is open and the pressure and spent air within the assembly vents to the atmosphere.

United States Patent Lindsey et al. 1 May 23, 1972 4] RESPIRATION ASSENIBLY AND Primary Examiner-Richard A. Gaudet METHODS Assistant Examiner-G. F. Dunne AnomeyLynn G. Foster [72] Inventors: Joseph W. Lindsey; Larry 0. Murphy,

both of Salt Lake City, Utah 57 ABSTRACT Assign: mo'Logicsa -i Salt Lake City, Utah A respiration assembly and methods, the assembly comprising [22] Filed; Apt 15, 1970 only a few nebulizing and exhalation valve components, forcefit together and disposable after short usage. Air is delivered PP 28,887 during the inspiration phase of the respiration cycle from a conventional respirator to the assembly in the form of a low pressure main stream flow and a high pressure nebulizing flow, {iii ii'fi'if'jiijijjjjijjj:'"""'"""13:33::.'.tjjjjjjijjffffifilfiii133 theexhalafionvalvebemwosebxdiswndmganepandawe 58 Field olSeanh ..128/194 185 186 188 195 bladde under Pressure- Nebulmm by 128]93 45.5 1458 1 A the high pressure flow through a constriction causing fluid from a cup reservoir to be siphoned to the site of discharge where shearing action of the effluent air against the liquid [56] References Cited results in an aerosol of small liquid particles. The aerosol is UNITED STATES PATENTS further broken up by a baffle, disposed immediately downstream of the orifice within the cup reservoir. The 3,362,404 1/1968 Beasley ..128/ 145.8 aerosol is purged f the cup reservoir and carried to and 3,172,406 3/1965 f e! 128/194 mixed with the main stream air flow by diverting a portion of 3,191,596 6/1965 B rd et al. ..l28/ 145.5 the main Stream fl through the cup. D i h expiration 3,537,448 11/1970 Liston 128/145- phase f th r iration cycle, no air flow occurs, the exhala- 3,02 l Hallamore et 1 ion valve is open and the pressure and pent air within the assembly vents to the atmosphere.

l2 Clains, 7 Drawing Figures Respirator PATENTEDMAY 23 I972 SHEET 1 [IF 3 Respirator INVENTORS JOSEPH W. LINDSEY LARRY 0. MURPHY mzmmmzam 3.664.337

SHEET 2 1F 3 IIIJ LIIIIIIIIII mvam'oas JOSEPH w. LINDSEY LARRY'O. MURl-IY BYZ I ATTO EY PATENTEDMAYZS 1912 3. 664, 337

SHEET 3 BF 3 INVENTORS JOSEPH W. LINDSEY LARRY O. MU HY ATTONEY RESPIRATION ASSEMBLY AND METHODS BACKGROUND 1. Field of Invention The present invention relates generally to the biomedical field and more particularly to a novel respiration assembly and unique methods for inhalation therapy.

2. Prior Art Known inhalation therapy apparatus, for nebulizing a stream of air from a respirator, comprises the respirator source of air which is channeled to a patient through a nebulizing chamber where an aerosol is created and mixed with the air during inspiration. An exhalation valve of the apparatus discharges spent air during expiration. However, such nebulizing apparatus has required a large number of parts, which are expensive to make, assemble and maintain. Thus, repeated reuse following sterilization has been an economical requirement, which risks degradation of the aerosol-generating function and cross contamination, if sterilization is incomplete.

Known simplified nebulizers are not intended for or capable of use with a respirator for inhalation therapy treatment.

BRIEF SUMMARY AND OBJECTS OF THE PRESENT INVENTION The present invention provides inexpensive, novel respiration apparatus and methods, to be used with a respirator for clinical or home inhalation therapy treatment. The components of the assembly are preferably of economical molded plastic and, for the most part at least, press-fit together.

Air under pressure from the respirator during inspiration creates a fine aerosol in a nebulization chamber by air-liquid shearing action at a nozzle effluent, using liquid siphoned from a reservoir by negative pressure existing adjacent the effluent. The aerosol may be further broken down by use of a baffle facing the nozzle efiluent and is purged from the nebulization chamber to the user by diverted main stream air flow originated by the respirator. A unique exhalation valve vents spent air and system pressure to the atmosphere during expiration.

It is a primary object of the present invention to provide novel respiration apparatus and methods for use with a respirator during home or clinical inhalation therapy treatment.

Another paramount object of this invention is the provision of a novel assembly and methods for creating and delivering nebulized air to a user during inspiration and venting pressure and air from the assembly during expiration.

, It is another important object to provide a novel and economical nebulizer, which is medically proficient to deliver an aerosol which provides humidity and, if desired, a medicant to an air stream during inhalation therapy, the nebulizer comprising plastic components force-fit together and being disposable after short usage.

These and other objects and features of the present invention will become more fully apparent from the following description and appended claims taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective representation of a presently preferred respiration assembly according to the present invention with diagrammatic representations depicting the manner in which the respiration apparatus is connected to a respirator;

FIG. 2 is an exploded perspective representation of the respiration assembly of FIG. 1;

FIG. 3 is a longitudinal cross section taken along line 3--3 of FIG. 1;

FIG. 3a is an enlarged fragmentary cross sectional view illustrating the interrelationship between the bladder head and the bladder of the exhalation valve;

FIG. 4 is an enlarged transverse cross section taken along line 4-4 of FIG. 1; and

FIGS. 5 and 6 diagrammatically illustrate fluid flow within the respiration assembly during expiration and inspiration, respectively.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT THE RESPIRATION ASSEMBLY Reference is now made to FIGS. 1-4, inclusive, which illustrate a presently preferred respiration assembly, generally designated 10. The respiration assembly is adapted to function in conjunction with a suitable respirator. For example, an intermittent positive pressure breathing (IPPB) respirator, generally designated 12, can be used. The IPPB respirator 12 is described as having the capability of intermittently delivering a main stream of gas (such as air) through conduit 14 at a desired rate and under a relatively low pressure during inspiration. The respirator 12 is also capable of intermittently delivering a minor stream of gas through conduit 16 during the same time interval at a desired rate and under a comparatively large pressure. Lastly, the respirator l2 cyclically delivers a fluid under relatively low pressure to conduit 18 only during inspiration of the respiration cycle.

The illustrated respiration assembly 10 is completely disposable and comprised of five major components which are force-fit together, i.e. a nebulizer body, generally designated 20, a valve or bladder head, generally designated 22, a bladder generally designated 24, a nozzle, generally designated 26, and a cup or reservoir, generally designated 28.

The nebulizer body or manifold 20 is one-piece injection molded from a suitable synthetic resin, such as polypropylene. The body 20 comprises a main stream airflow barrel 30 defining a through bore or passage 32. One end 34 of the barrel 30 comprises main stream gas influent structure while the other end comprises a two way channel 36 which accommodates air flow to the user during inspiration and exhaust air flow away from the user during expiration.

The bore 32 of the barrel 30 is illustrated as being interrupted only by an diagonally disposed baffle 38 (FIGS. 3 and 4). The baffle 38 is formed during molding integral with the remainder of the body 20 and projects into the bore 32 a minor distance to shunt part of the main stream flow through a port 40 in the barrel 30 into the cup 28. The shunted part of the main stream flow purges or scours nebulized air from an air space within the cup 28 through another port 42 into the barrel 30, the port 42 being larger in area than the port 40 and disposed downstream of the baffle 38.

The nebulizer body 20 also comprises a top opening or exhalation port 44 (FIG. 3) in the barrel 30. The exterior of the barrel 30 merges into an array of yieldable fingers 46 with memory disposed upward and generally transverse to the axis of the barrel. When taken together, the fingers 46 are disposed concentric about and axially parallel to the port 44. The yieldable fingers 46 are integrally carried upon a flat base 48, which defines a raised lip 50 adjacent the port 44 and extends laterally in both directions beyond the dimensions of the barre] 30. To accommodate rapid expulsion of spent air during expiration, the exhalation port 44 is preferably of a diameter equal or nearly equal to the diameter of the barrel bore 32.

The internal arcuate surface 52 of each resilient finger is interrupted toward the distal end thereof by a horizontal groove 54 and a tapered tip 56, the grooves 54 accommodating releasable holding of the bladder head 22 following disp1acement of the head 22 down the ramp surfaces 56 of the fingers. Since the fingers are yieldable, the assembled press-fit retention of the bladder head 22 by the resilient fingers 46 may be readily broken by manually elevating the bladder head 22 relative to the body 20.

The nebulizer body 20 also comprises an integral, generally circular cap 60 adapted to receive the upper open end of the cup 28. The cap 60 defines a circular, downward-extending flange 62, an annular groove 64 being disposed at the inside surface of the flange 62 immediately adjacent the flat top 66 (FIG. 4).

As best illustrated in FIGS. 1 and 2, the cap merges into an upward-extending boss 68 which, in turn, merges laterally into the wall of the barrel 30. A tapered, stepped bore 69 (FIG. 2) is disposed within the boss defining a central axis essentially parallel to but offset from thecentral axis of the cup 28 when assembled. The tapered stepped bore in the boss 68 comprises a comparatively large tapered bore portion 70 defining an annular groove 72. A shoulder 74 exists between the comparatively large bore portion 70 and the smaller tapered bore portion 76.

The bottom 78 of the bore is downwardly tapered merging with an orifice 80 which provides communication between the bore 69 and the interior of the cup 28 (FIG. 4). The smaller tapered portion 76 of the bore defines a side siphon groove 82 which communicates with a depending hollow siphon stem 84 also comprising an integral part of the nebulizer body 20. A length of flexible siphon tubing 86 is press-fit upon the stem 84 and depends therefrom to near the bottom of the cup 28 for the purpose of drawing liquid, with or without medicament, from the cup into the bottom of. the tapered stepped bore 69.

The underside 88 of the cap 66 defines an elongated cavity 90 with oppositely disposed small ridges 92. An elongated button 94 of a baffle framework 96 is press-fit within the cavity 90 and there retained by grooves 98 which mate with the ridges 92. The remainder of the one-piece baffle framework 96 comprises spaced angular arms 100 which support and retain an erect battle 102, the upper surface 104 of which is closely spaced from the orifice 80 for a purpose hereinafter to be explained. An offset stop 105, molded with the baffle 102, extends to and forceably engages the lower surface 107 of the bottom of the tapered bore 69 next to the orifice 80. Thus, the distance between the orifice 80 and the baffle surface 104 is precisely set and maintained.

The bladder head 22 is preferably injection molded of suitable synthetic resin, such as polypropylene. The bladder 24 is also preferably injection molded of a highly yieldable, synthetic resin with memory, such as vinyl. Together, the bladder head 22, the port 44 and the bladder 24 comprise an exhalation valve.

The bladder head 22 comprises an erect hollow stem 110 with a barbed fitting l 12 (FIG. 3). The stem 1 l0 merges into a sloped cover disc 114. The tapered cover 114 terminates in a radial rib 116 which, in the assembled condition, is snugly received in and held at the grooves 54 of the fingers 46. The bladder head 22 also comprises a circular, downwardly extending flange 118 defining an outwardly projecting lip 120.

The bladder 24 comprises an upstanding flange 122 which snugly fits around the circular flange 118 of the bladder head 22, a female groove 124 mating with the lip to retain the relationship and create a seal. The bladder, therefore, defines a diaphragm 126, with the cover one-fourth of the bladder head 22 and the diaphragm 126 of the bladder 24 defining a hollow inflatable chamber 131 therebetween.

With reference to FIG. 4, the nozzle 26 is preferably formed of injection molded synthetic resin, such as polypropylene. The nozzle comprises an erect, upwardly extending, conduitcoupling stem which defines a hollow interior 132 continuing through the nozzle and terminating in a constriction 134. The central body 136 of the nozzle comprises a plurality of material-saving recesses 138. The exterior shape of the nozzle allows the nozzle to be mated accurately with the previously described tapered bore or nozzle cavity 69, the shoulder 140 of the nozzle resting upon the shoulder 74 of the boss 68 and the peripheral lip 142 of the nozzle snugly fitting within and creating a seal at the previously mentioned recess 72 of the boss 68 in the assembled condition. Thus, the nozzle 26 is press-fit within the nozzle cavity 69 and, in that position, a chamber 144 is formed between the lower end of the nozzle and the tapered bottom 78 of the nozzle cavity.

The medicant cup 28 is preferably of one piece injection molded construction formed of suitable synthetic resin, such as polypropylene. The cup comprises a cylinder interiorly hollow at 152 and terminating in a downwardly directed skirt 154, which skirt accommodates a stable support of the respiration assembly 10 upon a desk top or the like in a generally horizontal attitude. The cup comprises a lip 156 on its upper surface at the outside diameter thereof which mates with and creates a seal at the groove 64 of the previously mentioned cap 60 in the assembled position (FIG. 4) thereby retaining the cup to the ncbulizer body 20. The bottom of the cup 28 is closed by an integral inverted cone-shaped plate 160. The hollow interior 152 of the cup 28 comprises a liquid reservoir at the bottom thereof, which liquid may comprise medicant, and an atomizing chamber at the top thereof, as will hereinafter be more fully described.

In use, a mouthpiece, generally designated 170, is used. The mouthpiece is illustrated as having an axial passage 172 communicating during use with the mouth of the user at opening 174 and with the hollow bore 32 of the barrel 30 at opening 176. The mouthpiece is preferably formed by injection molding synthetic resin and defines a reduced outside diameter 178 adjacent the opening 176 which is sized and shaped to be press-fit into and thereby retained at the bore 32 of the barrel 30 remote from the conduit 14. It is to be appreciated that any other suitable mouthpiece or, alternatively, other available connecting structure could be provided.

THE OPERATION With specific reference to FIGS. 5 and 6 and assuming the respirator 12 to be operating, i.e. (a) supplying a main stream air flow through conduit 14 to the barrel 30 during inspiration, (b) supplying a minor stream of air flow through the conduit 16 to the nozzle 26 during inspiration and (c) intermittently pressurizing the conduit 18 and the chamber 131 between the bladder head 22 and the bladder 24 during inspiration, the operation of the respiration press-fit disposable assembly 10 will now be described.

With the respirator 12 so cycled, the diaphragm 126 of the bladder 24 will be expanded or distended by low pressure in chamber 131 and sucked down by inspiratory sub-ambient pressure exerted by the user. Air under comparatively high pressure will reach the bore 132 of the nozzle 26 through conduit l6 and air under relatively low pressure will reach the bore 32 of the barrel 30 from the respirator 12 through the conduit 14. Thus, the conditions diagrammatically illustrated in FIG. 6 exist, wherein the exhalation valve is closed and incoming air is prevented from leaving the respiration assembly 10 except through the mouth of the user.

Air passing through the nozzle 26 into the nozzle cavity or chamber 144 exits through the orifice 80 disposed at bottom center of the nozzle cavity. The air flow through the nozzle 26 is essentially perpendicular to the plane of the orifice 80 and collinear with the center line of the orifice. Ordinarily, the area of the orifice 80 is selected to be slightly larger than the area of constriction 134 of the nozzle 26, thus allowing the jet of air to easily pass directly through the orifice.

Friction between the air molecules in the air jet from the nozzle and the air molecules in the nozzle cavity results in the noule cavity air being drawn out of the cavity 144 with the jet air nozzle. Thus, a low pressure region is created within the nozzle cavity 144, sucking liquid from the bottom of the cup up the plastic tube 86, through the depending stem 84 and siphon groove 82 into the nozzle cavity 144.

The liquid, which may be water, with or without medicant, or another solution, flows, by virtue of gravity and pressure, down the bottom surface of the nozzle cavity 144 toward and into the exit orifice 80. At the orifice 80 the liquid is inter cepted by the high velocity air jet stream issuing from the constriction 134 of the nozzle 26. The intersection of the two fluids, which have widely varying viscosities and velocities, results in a violent shearing action at the exit orifice 80. To prevent coalescence and re-mixing of the liquid, the exit orifice 80 is preferably extremely short in length.

The violent shearing action between the jet air stream merging from the nozzle and the liquid results in the creation of an aerosol of very small entrained liquid particles which emerge from the orifice 80 into the hollow upper portion of the cup 28. The aerosol contains a wide spectrum of particle sizes, some of which are too large for proper use in the respiratory system of a human being.

To obtain a usable and consistent sized aerosol, an erect baffle finger 102 is held in the cup immediately downstream and precisely in line with the effluent emerging from the orifree 80. The optimum distance between the orifice 80 and the top surface 104 of the baffle 102 will depend upon a number of factors, including pressures, air flow rates, liquid flow rate, dimensions of parts and the like. As the aerosol spray egresses from orifice 80 and impinges on the top surface 104 of the baffle 102, an additional break-up of liquid particles is achieved and the size spectrum of the liquid particles so altered that nearly all of the particles are in a size range suitable for use in the lungs of the user.

A minor portion of the main stream air flow through the barrel 30 impinges upon the diagonally oriented baffle 38 (FIGS. 3 and 4) in the barrel 30 and is directed into the space within cup 28 above the liquid, where the mentioned nebulization is taking place. This diverted air flow serves to scour or purge the cup of its usable aerosol, returning the diverted carrier air with the aerosol to the bore 32 of the barrel 30 through port 42. The directed flow of the carrier air through the cup 28 and the merging of the carrier air with the remainder of the main stream air flow in bore 32 mixes the aerosol with the main stream air flow, humidifying it and generally uniformly distributing any entrained medicant as the flow continues through the barrel 30 and into the respiratory system of the user.

At the point in time when the inspiration phase of the respiration cycle has been concluded, the patient is no longer exerting sub-ambient pressure in the bore 32 of the barrel 30 and the low pressure on the exhalation valve bladder 24 is released by the respirator 12. Thus, the bladder returns from its distended position to a relaxed position free from the lip 50 (F IG. 2) at the exhalation port 44.

The complete system, from the respirator to the patient, is pressurized above atmospheric pressure during inspiration and, therefore, when the exhalation valve bladder is open as mentioned, the pressure of the system becomes atmospheric and expired air vented through the exhalation valve. The exhalation valve can be so sized and constructed to retard the user's exhalation rate, if desired. At the same time, the flow through the nozzle 26 is interrupted by the respirator and production of aerosol ceases, Likewise, the main stream flow is interrupted by the respirator at this time and exhalation from the lungs of the patient through the mouthpiece 170, the portion of the barrel 30 comprising chamber 36 and out the exhalation port 44 beneath the bladder 24 and between the finger projections 46. Thus, the conditions generally diagrammatically illustrated in the H6. 5 prevail.

When the expiration phase of the respiration cycle is concluded, the system is set to and will commence another respiration cycle, in the manner described above. While the operation of the respiration assembly has been described in conjunction with an intermittent positive pressure breathing respirator, it is to be appreciated that other suitable respirators could be used.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of a the claims are therefore to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. In a method of inhalation therapy, the steps of:

delivering air or the like to first and second ingress locations of a closed manifold,

closing an exhalation valve and retaining the valve closed by pressure which distends a diaphragm into sealed relation with an exhalation port,

constricting flow of air from the first ingress location to increase velocity and create a negative pressure,

drawing liquid from a source to the constricted air flow by force of the negative air pressure,

shearing the liquid by force of the constricted air to create an aerosol in a nebulization chamber,

deflecting a portion of the air from the second ingress location within the closed manifold through said nebulization chamber to mix with said aerosol,

delivering the mixture to the respiratory system of a user,

and

thereafter opening said exhalation valve in the manifold venting expired air and manifold pressure to the atmosphere.

2. In a method as defined in claim 1 further comprising: impinging the sheared liquid and constricted air flow upon a baffle immediately following the shearing step thereby further breaking-up liquid particles of the aerosol.

3. In a method as defined in claim 1 wherein the mixing step comprises displacing at least part of the air from the second ingress location circuitously through the nebulization chamber, purging aerosol from the chamber and co-mingling aerosol with air.

4. In a method as defined in claim 1 further comprising the step of discontinuing delivery of air to the manifold during the last-mentioned opening step.

5. A nebulizer, adapted to be interposed between a respirator and the respiratory system of a patient, comprising:

liquid storage container means including a nebulization chamber above the liquid;

one-piece manifold structure to which the liquid storage container is releasably joined in sealed relation, the manifold structure comprising channel means receiving nebulized air from the nebulization chamber and delivering it to the user during inspiration and receiving expired air from the patient during expiration, exhalation port means in the channel means downstream from said liquid storage container, major air influent means in said manifold communicating air to the respiratory system of a patient, minor air influent means communicating with the nebulization chamber to nebulizer air, and means defining a liquid flow path from the stored liquid to the minor air influent means;

nozzle means releasably joined to the manifold structure immediately upstream of the minor air infiuent means to constrict minor air flow thereby developing a negative pressure which draws liquid along the liquid flow path to the minor air influent means where it is nebulized by the constricted minor air flow;

flow diverting means in said manifold to divert part of the flow through said major air influent means into said ne bulization chamber pressure inflatable valve means releasably joined to the manifold structure adjacent but in spaced relation to the exhalation port means to communicate expired air to the atmosphere when the valve means is not under pressure during expiration and to expand and close the exhalation port means when the valve means is under pressure during inspiration.

6. A nebulizer as defined in claim 5 wherein the liquid storage container means is force-fit into joined and sealed relation with the manifold structure and comprises a skirt adapted to rest upon a generally flat surface.

7, A nebulizer as defined in claim 5 wherein the inflatable valve means comprises a bladder housing and a resilient bladder together defining an expandable chamber and wherein the inflatable valve means is force-fit into retained relation with an array of spaced yieldable fingers with memory, the fingers comprising part of the manifold structure.

8. A nebulizer as defined in claim further comprising means providing open communication of major air flow directly from the major air influent means to the channel means and further comprising baffle means shunting a portion of the major air flow through the nebulization chamber to the channel means.

9. A nebulizer as defined in claim 5 wherein the nozzle means is releasably held to the manifold structure by force-fit retaining structure, wherein the minor air influent means comprises an orifice surrounded by a tapered surface to cause gravity flow of liquid, and wherein the liquid flow path comprises a liquid-receiving nozzle chamber comprising a space between the flow-constricting end of the nozzle means and the tapered surface and orifice, where the liquid flows and is nebulized by the constricted air flow.

10. A nebulizer as defined in claim 5 further comprising a baffle means aligned with and spaced a very small distance from where the liquid is first nebulized by the constricted air flow.

11. A nebulizer as set forth in claim 10 wherein the baffle means is supported by framework means carried in force-fit relation by the manifold structure.

12. A nebulizer as defined in claim 10 wherein the bafi'le means further comprises an offset stop projecting toward and contacting the minor air influent means whereby the mentioned small distance is precisely set and maintained. 

1. In a method of inhalation therapy, the steps of: delivering air or the like to first and second ingress locations of a closed manifold, closing an exhalation valve and retaining the valve closed by pressure which distends a diaphragm into sealed relation with an exhalation port, constricting flow of air from the first ingress location to increase velocity and create a negative pressure, drawing liquid from a source to the constricted air flow by force of the negative air pressure, shearing the liquid by force of the constricted air to create an aerosol in a nebulization chamber, deflecting a portion of the air from the second ingress location within the closed manifold through said nebulization chamber to mix with said aerosol, delivering the mixture to the respiratory system of a user, and thereafter opening said exhalation valve in the manifold venting expired air and manifold pressure to the atmosphere.
 2. In a method as defined in claim 1 further comprising: impinging the sheared liquid and constricted air flow upon a baffle immediately following the shearing step thereby further breaking-up liquid particles of the aerosol.
 3. In a method as defined in claim 1 wherein the mixing step comprises displacing at least part of the air from the second ingress location circuitously through the nebulization chamber, purging aerosol from the chamber and co-mingling aerosol with air.
 4. In a method as defined in claim 1 further comprising the step of discontinuing delivery of air to the manifold during the last-mentioned opening step.
 5. A nebulizer, adapted to be interposed between a respirator and the respiratory system of a patient, comprising: liquid storage container means including a nebulization chamber above the liquid; one-piece manifold structure to which the liquid storage container is releasably joined in sealed relation, the manifold structure comprising channel mEans receiving nebulized air from the nebulization chamber and delivering it to the user during inspiration and receiving expired air from the patient during expiration, exhalation port means in the channel means downstream from said liquid storage container, major air influent means in said manifold communicating air to the respiratory system of a patient, minor air influent means communicating with the nebulization chamber to nebulizer air, and means defining a liquid flow path from the stored liquid to the minor air influent means; nozzle means releasably joined to the manifold structure immediately upstream of the minor air influent means to constrict minor air flow thereby developing a negative pressure which draws liquid along the liquid flow path to the minor air influent means where it is nebulized by the constricted minor air flow; flow diverting means in said manifold to divert part of the flow through said major air influent means into said nebulization chamber pressure inflatable valve means releasably joined to the manifold structure adjacent but in spaced relation to the exhalation port means to communicate expired air to the atmosphere when the valve means is not under pressure during expiration and to expand and close the exhalation port means when the valve means is under pressure during inspiration.
 6. A nebulizer as defined in claim 5 wherein the liquid storage container means is force-fit into joined and sealed relation with the manifold structure and comprises a skirt adapted to rest upon a generally flat surface.
 7. A nebulizer as defined in claim 5 wherein the inflatable valve means comprises a bladder housing and a resilient bladder together defining an expandable chamber and wherein the inflatable valve means is force-fit into retained relation with an array of spaced yieldable fingers with memory, the fingers comprising part of the manifold structure.
 8. A nebulizer as defined in claim 5 further comprising means providing open communication of major air flow directly from the major air influent means to the channel means and further comprising baffle means shunting a portion of the major air flow through the nebulization chamber to the channel means.
 9. A nebulizer as defined in claim 5 wherein the nozzle means is releasably held to the manifold structure by force-fit retaining structure, wherein the minor air influent means comprises an orifice surrounded by a tapered surface to cause gravity flow of liquid, and wherein the liquid flow path comprises a liquid-receiving nozzle chamber comprising a space between the flow-constricting end of the nozzle means and the tapered surface and orifice, where the liquid flows and is nebulized by the constricted air flow.
 10. A nebulizer as defined in claim 5 further comprising a baffle means aligned with and spaced a very small distance from where the liquid is first nebulized by the constricted air flow.
 11. A nebulizer as set forth in claim 10 wherein the baffle means is supported by framework means carried in force-fit relation by the manifold structure.
 12. A nebulizer as defined in claim 10 wherein the baffle means further comprises an offset stop projecting toward and contacting the minor air influent means whereby the mentioned small distance is precisely set and maintained. 